The present invention relates to a novel L-glutamic acid-producing bacterium and a method for producing L-glutamic acid by fermentation using the same. L-Glutamic acid is an important amino acid as food, drugs and the like.
L-Glutamic acid has conventionally been produced by fermentation methods utilizing the so-called coryneform L-glutamic acid-producing bacteria which principally belong to the genera Brevibacterium, Corynebacterium, and Microbacterium or variants thereof ("Amino Acid Fermentation", Gakkai Shuppan Center, pp.195-215, 1986). As methods for producing L-glutamic acid by fermentation utilizing other bacterial strains, there have been known the methods utilizing microorganisms of the genera Bacillus, Streptomyces, Penicillium and the like (U.S. Pat. No. 3,220,929), the methods utilizing microorganisms of the genera Pseudomonas, Arthrobacter, Serratia, Candida and the like (U.S. Pat. No. 3,563,857), the methods utilizing microorganisms of the genera Bacillus, Pseudomonas, Serratia and the like or Aerobacter aerogenes (currently referred to as Enterobacter aerogenes) (Japanese Patent Publication (KOKOKU) No. 32-9393(1957)), the method utilizing variant strains of Escherichia coli (Japanese Patent Application Laid-Open (KOKAI) No. 5-244970(1993)) and the like.
Though the productivity of L-glutamic acid has considerably been improved by breeding of such microorganisms as mentioned above or improvements of production methods, it is still desired to develop a more inexpensive and more efficient method for producing L-glutamic acid in order to meet the expected markedly increasing future demand of the amino acid.